Answer: $11.81✔️cost of the sandwich before tax
Explanation:
Let C = cost before tax
Cell phone costs = C + C·5% = $12.40
C(1 + 0.05) = $12.40
C = $12.40/1.05 = $11.81 , cost before tax
Answer: $11.81✔️ cost of the sandwich before tax
Checking
Cell phone after tax = $11.81 + $11.81·5/100
Cell phone after tax = $11.81 + $0.59 = $12.40✔️checked!
Spymore